In order to determine the height of the model for the Emeral-Shapley Center, determine the scale factor in between the actual size and model, by using the information about the American plaza:
scale factor = 500 ft/ 10 in =50 ft/in
which means, that there are 50 feet in 1 inche of the model.
Then, to obtaine height of the Emerald-Sapley Center, divide the actual height over the scale factor:
450 ft/(50 ft/in) = 9 in
Hence, the height of the model for Emerald-Shapley center is 9 in